geography section B and C

what is an ecosystem?

an ecosystem is a community of living organisms interacting with their non living environment

what is a producer?

a producer is a living organism that makes it own food, usually through photosynthesis

what is a consumer?

a consumer is an organism that cannot make its own food and must obtain energy by eating other living things

what is a decomposer?

a decomposer is an organism, like bacteria or fungi, that breaks down dead plants and animals

what is the nutrient cycle?

the nutrient cycle is the circulation of nutrients between biotic and abiotic components

what are nutrients stored in?

soil, biomass, and litter

how can nutrients be transferred between the stores?

plant uptake, littering, decomposition

how are nutrients brought into the cycle?

rainfall, weathering of parent rock

how do nutrients escape the cycle?

surface run off, leaching

what is an example of a small scale ecosystem?

the river tay

what is a producer found in the river tay?

water lily, willow tree, and aspen tree

what is a consumer found in the river tay?

beaver, pike, water beetle

how did the components of the river tay change?

• leaves from deciduous trees and felled wood accumulate in the litter layer of the forest floor and are broken down by bacteria

• the willow and aspen tree are deciduous and will shed leaves

• the white water lily and willow trees are producers and consumed by the beavers

• beavers add biomass to the ground by feeling trees for food and to create dams

• damming from the 150 beavers in the tay area creates more flooded areas

• increases in the number of water beetle due to flooded areas leads to increased numbers of pike

what is a biome?

a biome is a large scale ecosystem that can spread across countries/ continents

where is the rainforest located?

it is found in an area of low pressure in a band located on the equator

what is the climate like in the rainforest?

• wet and dry seasons

• high levels of rainfall

• temp is 28c on average

• earth is less curved so the suns energy is concentrated on a small area

wha is the soil like in the rainforest?

• infertile soils due to leaching caused by high rates of rainfall

• nutrients return to the soil quickly due to high rates of decomposition

what is the biodiversity like in the rainforest?

• the most diverse biome

• plentiful producers so consumers thrive

• home to half of the world plant/animal species

• 4 layers:

  emergent - tallest trees

  canopy - blocks out sunlight

  under canopy - tree trunks

  forest floor

what are buttress roots?

roots that grow out from the tree trunk and help support the tree, they grow on top of the soil

what challenge do buttress roots overcome and why does this challenge exist?

infertile soil - excessive rainfall and leaching

what are epiphytes?

• vines that attach to other plants to capture their water and their nutrients

• allows them to overcome the lack of nutrients (infertile soils due to excessive rainfall and leaching) on the forest floor

how are sloths adapted?

• they grow moss on their fur to camouflage

• they move slowly to save energy

• they do this to protect themselves from predators

where are deserts located?

found on the Tropic of Cancer and Capricorn - this is an area of high pressure

what is the climate like in the desert?

• Daytime temps are very high (can get to 50c)

• 250mm of rainfall per year

• air doesnt rise and condense to form clouds - it is an area of high pressure

• night-time temps drop significantly, no clouds to insulate and trap heat

what is the soil like in the desert?

• infertile, sandy, rocky

• soaks up water quickly

what is the biodiversity like in the desert?

• far lower than other ecosystems due to extreme environmental challenges

what is a plant and an animal that is adapted to the desert?

• camel - nostrils to keep sand out, long eyelashes to protect from sand, large tough lips to eat dry thorny vegetation

• cacti - spines fend off predators, stores water for future use, thick waxy skin to reduce loss of water and to reflect heat

what challenge does extreme temps pose?

• farming - impacts livestock health

• tourism - people don’t want to go out because it’s too hot

what challenge does accessibility pose?

• transport is difficult due to extreme weather conditions

• high temps can cause tarmac roads to soften and melt

• public transport is limited

• tourism - difficult to get around

what is an example of a place that has experienced desertification?

the Sahel region - it was once savanna grasslands but is now a desert

what are two causes of desertification?

• population growth - population stays high due to a lack of education so the number of cattle kept is increased, increasing the vegetation being consumed

• overgrazing - if the cattle graze on one site for too long they can eat all the vegetation and it may not be able to regrow

what is a management strategy for desertification?

water and soil management -

• stones are laid along the contour lines of the land which traps the rainwater that falls off

• The stones slow down water run off and allows water to infiltrate into the ground

• this results in less erosion and more water for the crops

what is the benefits and costs of this strategy?

benefits:

• low cost

• skills are easily learnt

costs:

• hard labour

• importing costs